Extensible link



May s, 1928. 1,669,346

A. PAULSON EXTENSIBLE LINK Filed May 19. 1925 i 777. 6/. Z%7/M/ INVENTORW W4 Patented May 8, 1928.

UNITEDSTATES PATENT OFFICE.

ARTHUR PAULSON,

OF NEW YORK, N. Y., ASSIGNOR, BY DIRECT AND MESNE ASSIGN- MENTS, TOHARVARD HOLDING C ORI ORATION, OF NEW YORK, N. Y.

EXTENSIBLE LINK.

Application filed May 19, 1925. Serial No. 31,453.

My invention relates to an extensible link for supporting the dropfrontof cabinet files of the type shown in my copending application forcabinet files, Serial Number 746,560, filed October 29, 1924.

In the said application theextensible link consists of two strips oflight metal pivoted together at one end of each and having the otherends secured to a back and a drop front respectively.

In practice it has been found that when the front is pulled outviolently the joint between the strips occasionally rises above thedead-center position so as to obstruct the closing of the file.Furthermore if the front 3e closed violently it has been found that theextensible link will sometimes buckle in a transverse plane at the jointof the strips and fail to function.

It is an object of my invention to so modify the extensible link as toobviate these defects and still maintain the simplicity of structure andease of manufacture.

I havev shown in the drawing and will now describe the preferredembodiment of my invention, but it is to be understood that variouschanges may be made within the scope of my invention and that I do notintend to be limited except as specified in the claims.

Referring to the drawing, the figure shows a view of an extensible link,constructed according to my invention, and taken from the attaching sideand in opened position.

The extensible link consists of 2 relatively long strips of light metal1 and 2 of arcuate shape. The strip 1 is flat and has an opening 6 forengagement with a pivot on a movable member (not shown). The strip 2 isflat for the major part of its length but is provided at its end withportion 3 bent at right angles to the strip and having an attachingflange 4 bent parallel to the strip. The flange 4; has an opening 5 forengagement with a pivot on a fixed member. (not shown). At theirintermediate ends the strips 1 and 2 are pivoted together as at 8. Thestrip 2 at its intermediate end is provided with a flange 7 formed bybending over a portion of the metal and adapted to engage the strip 1when the extensible link is in the extended position shown.

Vihen the extensible link is operated to close, the joint 8 descends andthe two strips 1 and 2 approach, the offset 3, providing sufiicientspace for the movable member. The flange 7 provides sufiicient stiffnessat the joint to overcome the tendency to buckle transversely which isfound at the wide open position. When the extensible link has beenslightly closed, this tendency disappears and hinge closes freely.lVhen; the extensible link is opened the bottom of the channel formed bythe flange 7 engages the lower edge of the strip 1 and preventsoverrunning of the fully opened position. i

I claim:

1. An extensible link comprising two substantially flat arms pivoted toeach other ing an end bent over laterally adjacent the pivot to providea channel with rear and side walls adapted to, receive the other arm inone of its positions in such manner that an edge of the said other armengages the rear wall in approximately parallel rela tion.

ARTHUR PAULSON.

